Why the Data on Justifiable Homicide Just Won’t Do

The recent events in Ferguson, Mo., have raised questions about shootings by police in the U.S. and homicides that are ruled justifiable. Unfortunately, it’s nearly impossible to answer some of those questions due to incomplete data.

The FBI’s Uniform Crime Reporting Program collects data from the more than 18,000 law enforcement agencies to provide statistics about crime and law enforcement in the U.S. From this program, for example, we know that there were 14,827 homicides and non-negligent manslaughters in 2012, the latest year for available data. But, it isn’t required that agencies submit justifiable homicide data—submitted as the Supplementary Homicide Report—to participate in the program. This makes the largest database of justifiable homicides in the U.S. very incomplete.

Among the missing states is New York, which had 684 killings in 2012. The third-most populated state, which likely had a number of justifiable homicides, doesn’t report justifiable homicide data, according to the FBI. Data from other highly populous states are missing or compromised as well. Agencies from Florida don’t follow Uniform Crime Reporting guidelines when submitting justifiable homicide data and Illinois only submits limited data. Various other agencies at multiple levels don’t submit justifiable homicide data for other reasons, resulting in fewer than half of the 18,000 agencies contributing this information.

(As a side note, justifiable homicide data are available only as a text file—not very friendly for those of us looking to find answers by sorting numbers.)

These are early numbers for justifiable homicides printed in the FBI’s Crime in the United States annual publication. Totals often change slightly afterward, as agencies can continue handing in corrected data until the following December. Justifiable homicide is defined as a killing committed, either by police or private citizens, while the victim is in the process of committing a felony. Felonies can be anything from rape or robbery to gambling.

While the numbers for total killings in the U.S. rely on data from all reporting agencies as well as estimates for unreported areas, the numbers for justifiable homicides are just what’s reported. Law enforcement agencies aren’t required to submit justifiable homicide data as part of the Uniform Crime Reporting Program. Since the data are incomplete, it’s difficult to draw any conclusions from the data. The general uptrend just means that there are more reported justifiable homicides in the U.S. Because we don’t know what’s happening in areas that don’t report, it’s unclear whether the rate for the entire U.S. is the same, rising faster or even falling.

These are the data we do have on justifiable homicides. California has the most reported justifiable homicides by law enforcement; Texas the most by private citizens. But not all jurisdictions within the state report their data, so we can’t be sure of where states stand overall. Meanwhile, one must assume that if all law enforcement agencies were required to submit justifiable homicide data, these numbers would be much higher. New York would likely be high on the list instead of missing.

The chart below compares reported homicides/manslaughters, which is mandatory, with reported justifiable homicides, which aren’t required.

Without requiring law enforcement agencies to report justifiable homicides, the data will continue to underestimate the numbers of justifiable homicides in America, and will make it impossible to draw conclusions about what the data are saying.

About The Numbers

The Wall Street Journal examines numbers in the news, business and politics. Some numbers are flat-out wrong or biased, while others are valid and help us make informed decisions. We tell the stories behind the stats in occasional updates on this blog.